RE: [PATCH V4 04/24] xen/ioreq: Make x86's IOREQ feature common

[Paul Durrant <xadimgnik@xxxxxxxxx>]

> -----Original Message-----
> From: Oleksandr Tyshchenko <olekstysh@xxxxxxxxx>
> Sent: 12 January 2021 21:52
> To: xen-devel@xxxxxxxxxxxxxxxxxxxx
> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>; Andrew Cooper 
> <andrew.cooper3@xxxxxxxxxx>;
> George Dunlap <george.dunlap@xxxxxxxxxx>; Ian Jackson <iwj@xxxxxxxxxxxxxx>; 
> Jan Beulich
> <jbeulich@xxxxxxxx>; Julien Grall <julien@xxxxxxx>; Stefano Stabellini 
> <sstabellini@xxxxxxxxxx>; Wei
> Liu <wl@xxxxxxx>; Roger Pau Monné <roger.pau@xxxxxxxxxx>; Paul Durrant 
> <paul@xxxxxxx>; Jun Nakajima
> <jun.nakajima@xxxxxxxxx>; Kevin Tian <kevin.tian@xxxxxxxxx>; Tim Deegan 
> <tim@xxxxxxx>; Julien Grall
> <julien.grall@xxxxxxx>
> Subject: [PATCH V4 04/24] xen/ioreq: Make x86's IOREQ feature common
> 
> From: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>
> 
> As a lot of x86 code can be re-used on Arm later on, this patch
> moves previously prepared IOREQ support to the common code
> (the code movement is verbatim copy).
> 
> The "legacy" mechanism of mapping magic pages for the IOREQ servers
> remains x86 specific and not exposed to the common code.
> 
> The common IOREQ feature is supposed to be built with IOREQ_SERVER
> option enabled, which is selected for x86's config HVM for now.
> 
> In order to avoid having a gigantic patch here, the subsequent
> patches will update remaining bits in the common code step by step:
> - Make IOREQ related structs/materials common
> - Drop the "hvm" prefixes and infixes
> - Remove layering violation by moving corresponding fields
>   out of *arch.hvm* or abstracting away accesses to them
> 
> Also include <xen/domain_page.h> which will be needed on Arm
> to avoid touch the common code again when introducing Arm specific bits.
> 
> This support is going to be used on Arm to be able run device
> emulator outside of Xen hypervisor.
> 
> Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>

Reviewed-by: Paul Durrant <paul@xxxxxxx>